Protein composition of matter and method of making



Siormer V/scas/zy Seconds pef /00 Re volt/lions Aug. 7, 1945. LEVINSQN ETAL 2,381,407

PROTEIN COMPOSITION OF MATTER AND METHOD OF MAKING Filed July 51, 1940 V/scosny Curve -5xdm 0/e 5 O Inuenzo Fmefn Minutes Percy Anya):

fl/zdrew 6. 5,195 from flr/fiurfl. L e umson cdtd flttorng v (1) Water soluble proteins similar to Patented 7, 1945 e r v A umrso STATES I PATENT OFFICE PROTEIN COMPOSITION OF MATTER AND METHOD OF MAKING Arthur A. 'Levinaon, Chicago, Percy L. Julian; Maywood, and Andrew G. Engstrom, Itasca, lll., assignors to The Glidden Company, Cleveland, Ohio, a corporation of Ohio Application July 31, 1940, Serial No. 348,780

9 Claims.

lupins, etc. or from any other source containing vegetable globulin protein. More specifically the invention relates to the production of vegetable protein products readily soluble in water and which, depending upon the particular mode of treatment have a variety of uses, as willmore fully appear.

The single figure is a graph showing certain I features ofthe invention.

Natural seed materials such as soybeans contain proteins of various types which may be broadly classified as follows:-

albumin (2) Globulin proteins soluble in aqueous acid,

alkali and salt solutions (3) Prolamines or proteins insoluble except at high concentrations of acid and certain organic solvents.

The seed material also contains in addition to the water soluble albumin other water soluble substances such as sugars, glucosides, gummy materials and colored ingredients as well as insoluble alkali and material such as fiber including cellulose and hemicellulose.

' According to the present invention there is produced from the proteinaceous seed material or from other sources, particularly those containing globulin proteins, vegetable protein products which are readily soluble in water and which have many technical advantages over vegetable products heretofore produced. The vegetable protein products produced according to the present invention can be used for a variety of purposes such as foam retention and stabilizing agents in the preparation of icings, fillings, nougats, fondants and similar confections and food products, and in fact for any other use where foam retention and stability is desired; as textile sizings, etc. and for other purposes, depending in part at least upon the particular mode of treatment.

. ,The protein product produced according to the present invention is a water soluble proteinate. It has been found that if the globulin protein is separated from the water soluble constituents, and preferably also from the insoluble ingredients of the seed material and the isolated globulin treated with a'proteolytic enzyme that desirable advantages are obtained. Removal of water soluble constituents may be effected at any suitable stage in the process prior to the formation of the final proteinate. Thus, the seed material 'may be treated, leached or washed with water having an acidity such that the pH value corresponds substantially to that of the isoelectric pointof the globulin-protein- Under these conditions the water soluble constituents of material are soluble but washed to remove the water soluble constituents.

For example, the seed material such as soybean can be extracted with alkali, the extracted protein then precipitated by the addition of acid to the isoelectric point, the curd filtered and washed after which the final preparation of the alkali proteinate may take place. or as an alternative procedure the seed material can be extracted with water, the insoluble material separated and sufllcient acid added to precipitate the protein. The combination of these procedures may also be employed.

The enzyme hydrolysis is preferably effected by means of proteolytic enzymes, such as papain or "other papainases, etc. The enzyme is also preferably one which is active in alkaline conditions as in such a case the enzyme hydrolysis may be effected in a solutionof the final alkali subjected to a further hydrolysis by means of proteolytic enzymes that many desirable properties may be imparted to the alkali proteinate of the thus hydrolyzed proteins.

It has been observed that vegetable proteins such as the globulins of soybeans upon continued hydrolysis pass through a series of transformations from the sol to the gel stage,.and that the viscosity curve has points ofmaxima and minima. Thus when soybean protein is subjected to an alkaline hydrolysis the viscosity will first rapidly increase to a point of maxima or gel stage. which increase in viscosity is separate and distinct from mere solution viscosity. Thereafter the viscosity drops more slowly. If now the protein is hydrolyzed with an enzyme, such as papain for example, the viscosity will continue to decrease to a point of minima, the'time-viscosity curve of the enzyme treatment flattening out as the point of mimma is approached. After passing the point of minima the viscosity then rises rapidly again to a point of maxima or gel stage.

If the subsequent enzyme hydrolysis be stopped before the second point of gelation occurs, refthe seed erably "at or about the point of minimum viscosity, alkali proteinates or the thusiormed protein upon whipping with water form a still, nonseparating, light weight foam and the material can be used inplace oi egg albumin or egg white as a foam stabilizer in such confections as icings, fillings, nougats. iondants, etc. Upon whipping oi the thus formed proteinate with water a surface gelatin occurs which itis believed is responsible for the foam stabilizing'properties or the product. i

In addition to use in confections the enzyme hydrolysed material may be used tor other purposes where ioam stabilisation is desirable and may be used in both edible and non-edible products. Also, in certain cases desirable products are produced by enzymehydrolysis which do not show roam stabilizing properties but which none the less .have very desirable properties. Also, it is not essential that the enzyme hydrolysis be preceded by some other hydrolysesbut the enzwme hydrolysis is slower in such cases thanii the protein is first hydrolyzed by some other method such as byacids or'alkalies.

' Exsurrs 1' One part oi. soybean meal was extracted with j parts or water and the insoluble material sep-' arated from the water extract. Sumcient acid was then added to bring the pH down to 4.6 and the liquid containing thewater soluble constituents or the meal was separated from the precipitate. water at a pH 01 4.6 and the volume brought back to the original with water. 3% sodium hydroxide and 3% lime based on the'weight of the original flakes was added and thealkaline liquor thus i'ormed was digested at 110 'F. ior 12 hours after which the protein was precipitated by the addition or suflicient sulfuric acid to bring the pH down to approximately 4.6 after which the curd was dried. v One part of the thus prepared dried protein curd was dissolved in 3% parts of water by means or 3%% or dry sodium hydroxide by heating to 130 F. for thirty minutes. 1%% of papain by weight 01 the protein dispersed in water was then' added and the temperature broughtvup to 135 to 140 F. and the hydrolysis continued until the point of minimum viscosity was reached which occurred after 1% hours of heating at which time 1%% oi! hydrogen peroxide was added to stop the action 01 the enzyme. The point or minimum viscosity was determined by first hydrolyzing a small sample or the protein and plotting the time-viscosity curve to the point or gelation, the time being noted in which the minimumviscosity was obtained. The hydrogen peroxide was then added at the expiration of the predetermined elapsed time.

The solution thus formed was then dried on a drum dryer and the alkali proteinate thus formed ground to a suitable particle size. The

product thus formed was readily soluble in water and when so dissolved in water could be whipped to form a stifl, light weight, non-separating permanent loam comparable in all respects to that produced iromegg white or egg albumin. In place or drying the product the solution 01 the enzyme hydrolyzed alkali proteinate can be used directly if ieasible to -do so or a solution 1 may be further concentrated without complete Also in place of treating the dried curd the enzyme and alkali may be added to the wet curd The precipitate was then washed with aseacov %.protein and the mixtin-e heated. In such a case the mixture, at first pasty, immediately beginstogetthinnerandinashorttime has a watery consistency. I: too much'water is present in the filtered and washed curd the curd may also be pressed to remove as much oi. the water as possible in which case a more. concentratedsolutionisi'onned. Alsoinplaceo! treatingthe curd or dried protein the enzyme maybe added directly to the alkaline liquor after first adjusting the pH to the proper value ior enzyme activity.

Exunarx 2 250 parts 01' alkaline hydrolysed soybean protein prepared in the same manner as set forth in Example 1 was slurred with water at 115-120 F. 50 parts of borax dissolved in '15 parts oi. water at l15-120 F. was then added in increments with agitation, and the agitation continued until the protein was dissolved. 2.5 parts of a proteolytic enzyme having an E. E. value of 3500 on casein at pH 8.2 to 8.5 was then added, the ratio of .water to protein being brought up to 35:1. The digestion was continued for one hour, the temperature being maintained at 115-120 E. throughout. At the end of one hour the solution was pumped from the reaction vessel to a storage tank for a drum drier and the material dried on a drum drier.

The alkali protein thus formed does not possess the foam stabilizing property to the extent of that produced according to Example 1 but may be used as a substitute for gelatin in coatingsynthetic fibers such as cellulose acetate, and for other purposes.

Exempted I Table 1 f i s cos es Time in minutes oi pepsin action F925 gram 0 620. 12 39. 24 28. 32 25. 47 25. 02 24. 77 26. 98 27. 162 32. 187 37. 201 as. 242 47. 277 63. an 32, 342 104. 372 147. 417-.- 296. 462 385. 482 478. 502 625. 540- 640. 1.415. G

When the driedalkali proteinate is produced it is not necessary that drying be eflected by which contains approximately moisture and (I heating on a drum drier. Various other methods tor drying may be employed such as spray drying, vacuum drying, etc. In fact almost any method of drying may be employed which does not bring about a neutralization of the alkali in the proteinate. It has been found, however, that the solutions of the proteins of the present invention have an advantage over such proteins as casein in that the viscosities are sufflciently low to enable their being pumped and can be readily handled on a drum drier, spray drier, etc. Solutions of casein cannot be so handled, except at low concentrations due to the high viscosity of the solutions. On the other hand when casein is treated with such enzymes as papain a separation of the casein solution into two phases occurs, the material separating being of a very viscous stringy character with a supernatent liquid above it.

As previously mentioned the enzyme hydrolysis is preferably preceded by some other hydrolysis which may be eflected in various ways such as by acids, alkalis, etc. or by combinations thereof. Thus either acid or alkaline hydrolysis of the globulin proteins may be effected by digesting the globulin in either acid or alkaline dispersions or solutions. Heating and digesting at the isoelectric point as well as at lower pH values results in hydrolysis. However, as previously pointed out the hydrolysis should be such that the protein character is not substantially destroyed.

The preliminary hydrolysis may, however, be

eliminated and only an enzyme hydrolysis employed if desired.

Having described the invention what is claimed and desired to secure by Letters Patent of the United States is:

1. A water soluble composition of matter consisting essentially of an enzyme hydrolyzed alkali metal globulinate in dry form.

2. A water soluble composition of matter comprising an alkaline and enzyme hydrolyzed alkali metal globulinate in dry form,

3. A water soluble composition 01 matter comprising an alkaline and enzyme hydrolyzed alkali metal soybean globulinate in dry form.

4. The process which comprises hydrolyzing vegetable globulin protein with an enzyme, forming an alkali proteinate of said enzyme hydrolyzed globulin protein and recovering the same in dry form.

5. The process which comprises hydrolyzing soybean globulin protein with an enzyme, forming an alkali proteinate of said enzyme hydrolyzed globulin protein and recovering the same in dry form.

6. The process which comprises subjecting an isolated soybean globulin protein first to an alkaline hydrolysis, and then to a papain hydrolysis in an aqueous alkaline solution until approximately a point just short of that at which a rapid increase in viscosity and gelation commences is reached, and recovering the product in dry form.

'7. The process which comprises first hydrolyzing soybean globulin protein by means of an alkali to a point beyond that at which a maximum viscosity is produced and at which .the viscosity has been reduced from that of the maximum, continuing the hydrolysis by means of a papainase until approximately a point just short of that at which a rapid increase in viscosity and gelation commences is reached, forming an alkali metal proteinate oi the thus treated protein and recovering the same in dry form.

8. The process which comprises subjecting an isolated soybean globulin protein to a papain hydrolysis for a period of time between that substantially necessary to reach a point of minimum viscosity and that at which a rapid increase in viscosity and gelation commences, forming an alkali metal proteinate of the thus treated protein and recovering the same in dry form.

9. The process which comprises subjecting an isolated soybean globulin protein first to an alkaline hydrolysis and then to a papain hydrolysis for a period of time between that substantially necessary to reach a point of minimum viscosity and that at which a rapid increase in viscosity and gelation commences, forming an alkali metal proteinate of the thus treated protein and recovering the same in dry form.

AR'I'HUR A. LEVINSON.

PERCY L. JULIAN. ANDREW -G. ENG-STROM. 

